Screen printing machines



March 22, 1955 E. wALsH, JR f 2,704,510

SCREEN PRINTING MACHINES Filed July 5, 1952 4 sheets-sheet 1 INVENToR./55 EDGAR WALSH, JR.

BY @W w @Eg March 22, 1955 E. WALSH, JR

SCREEN PRINTING MACHINES 4 Sheets-Sheet 2 Filed July 5, 1952 INVENTOR.

l WALsHL BY @E9n/g w KIQ/i Afm/mw 4 Sheets-Sheet 3 Filed July 5, 1952INVENTOR.

EDGA'R WALSH, JR.

4 Sheets-Sheet 4 Filed July 5, 1952 INVENTOR.

EDGAR WALSH, JR. WQ@ W @M United States Patent O SCREEN PRINTINGMACHINES Edgar Walsh, Jr., St. Louis, Mo., assignor to Eugene Landesman,Clayton, Mo.

Application July 5, 1952, Serial No. 297,292

10 Claims. (Cl. 101-123) This invention relates in general to printingapparatus and, more particularly, to certain new and useful improvementsin screen printing machines.

The primary object of the present invention is to provide a screenprinting machine comprising a frame for carrying the operating partsthereof to present an integrated structure which may be mounted upon anysuitable work support member and which is adapted, when in installedposition, for vertical pivotal movement between substantially horizontalor printing position and tilted or inoperative position.

It is a further object of this invention to provide a screen printingmachine having a squeegee for reciprocal traversing movement with theprinting being accom plished thereby when the frame is in substantiallyhorizontal position, and novel control means associated with thesqueegee for selectively limiting the length of the printing stroke sothat work of varying sizes and shapes may be effectively accommodated.

It is an additional object of this invention to provide a screenprinting machine having latch means for locking the frame to the worksupport member during the printing stroke of the squeegee, which meansare adapted for disengagement in timed relation to the termination ofthe printing stroke to allow the frame to swing into inoperativeposition.

It is a still further object of this invention to provide a screenprinting machine having a paint scoop for travel with the squeegee,which is adapted to present paint upon the screen in advance of thesqueegee during the printing stroke for even distribution thereof.

It is an additional object of the present invention to provide a screenprinting machine having a frame which is so counterbalanced that uponcompletion of the printing operation it will rock upwardly so that thesqueegee will not effect any printing during its return stroke, and willreturningly rock downwardly into printing position when be squeegee hascompleted such return stroke.

It is a further object of this invention to provide a screen printingmachine which may be economically manufactured, which is reliable anddurable in use, and which may be easily operated.

With the above and other objects in view, my invention resides in thenovel features of form, construction, arrangement, and combination ofparts presently described and pointed out in the claims.

In the accompanying drawings (four sheets)- Figure l is a side view of ascreen printing machine constructed in accordance With and embodying thepresent invention, showing the squeegee at the beginning and at the endof the printing stroke;

Figure 2 is a transverse sectional view taken along line 2 2 of Figure1;

Figure 3 is a transverse sectional view taken along line 3 3 of Figure2;

Figure 4 is a transverse sectional view taken along line 4 4 of Figure3;

Figure 5 is a transverse sectional view taken along line 5 5 of Figure4;

Figure 6 is a transverse sectional view taken along line 6 6 of Figure2;

Figure 7 is a transverse sectional view taken along line 7 7 of Figure6;

Figure 8 is a transverse sectional view taken along line 8--8 of Figure6;

Figure 9 is a transverse sectional view taken along line 9-9 of Figure8;

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Figure 10 is a transverse sectional view taken substantially along line9 9 of Figure 8 showing the connecting link in relative upward position;

Figure 1l is a transverse sectional view taken along line 11 11 ofFigure 7;

Figures l2 and 13 are transverse sectional views taken altng lines 12-12and 13 13, respectively, of Figure ll; an

Figure 14 is a transverse sectional view taken along line 14 14 ofFigure 4.

Referring now to the drawings which illustrate a preferred embodiment ofthe present invention, A generally designates a screen printing machinewhich incorporates a frame 1, of welded sheet metal construction, forsupporting the operating parts thereof, whereby the machine A presents acompact unit for installation upon any selected work support member,such as a table B. In its rearward portion, with reference being made tothe right hand side of Figure l, the frame 1 is designed to provide anopen-bottomed, box-like housing 2 having a top wall 3, side walls 4, 4',and rearward and forward end walls 5, 6, respectively. Secured to theunder face of the top wall 3 is a bracket 7 for suspendingly supportingan electric motor 8 having a shaft 9 upon which are'mounted spacedpulleys 10, 11. Trained about the pulley 10 is one end of a straightV-belt 12 engaged at its other end about a sheave 13 fitted runningly,as by a bushing 14, upon a drive shaft 15 extending transverselybetween, and projecting at its ends through, suitable openings in theside walls 4, 4', said drive shaft 15 being journaled in bearings 16,16', bolted on said side walls 4, 4', respectively. Trained about thepulley 11 is one end of a crossed V-belt 17, the other end of whichextends about a sheave 18 also runningly tted upon the drive shaft 15,as by a bushing 19, in spaced relation to the sheave 13. Fixedly mountedon the drive shaft 15, as by welding, intermediate the sheaves 13, 18,is a friction clutch plate 20 having leather facings 21, 21',confronting the inwardly presented faces of the sheaves 13, 18,respectively, for selective frictional engagement therewith fortransmission of motion to the drive shaft 15. Outwardly of each sheave13, 18, there is slidably disposed upon the drive shaft 15, a thrustbearing 22, 22', respectively, for abutment on their inner surfaces withbushings 14, 19, respectively, and for contactive engagement on theirouter faces with the legs of U-shaped clutch dogs 23, 23', respectively,of a shifter member 24. The legs of each clutch dog 23, 23', arepresented on opposite sides of the shaft 15 and are pivotally secured attheir upper ends to the under face of housing 2 for lateral swingablemovement (see Figures 3 and 4). At their lower ends the clutch dogs 23,23', are connected to the ends of a turnbuckle adjustment 25 extendingtherebetween. Secured to clutch dog 23 adjacent its lower end by a linkpivot 26 is one end of a clutch shift link 27, the opposite or outer endof which is engaged to the end of the arm 28 of a bell crank 29fulcrumed upon a bracket 30 fastened to the inner. face of the rear endwall 5. The other arm 31 of bell crank 29 projects outwardly through anopen'- ing 32 in side wall 4' of housing 2 and at its outer ex tremityis connected to the rearward end of a control rod 33 which extendsforwardly in outwardly spaced relation to the adjacent side of frame 1for engagement at its forward end to the upper end of an operating lever34, having a handle grip 35 at its lower end; said lever 34 beingmounted for rockable movement at the forward end of frame 1 in a mannerto be described more fully hereinbelow.

With reference being now made to Figures 10 and 2 it will be seen thatwhen the lower or handle end of .operating lever 34 is rocked downwardlyand rearwardly, the upper end thereof will be swung forwardly causing apull to be applied to the control rod 33 whereby the bell crank 29 ispivoted to cause the shifter member 24 to be swung about the dog pivotsso that the clutch dog 23 engages thrust bearing 22 to move sheave 13into engagement with clutch plate 20 whereby the drive shaft 15 will berotated in the same direction to that of the motor shaft 9 since theV-belt 12 is straight. Conversely, if the lower or handle end ofoperating lever 34 is rocked upwardly and forwardly into the positionshown in Figure 9, a rearwardly directed motion or pushing will beeffected upon the control rod 33 with the bell crank 29 being pivoted sothat the shifter 24 will be swung to bring the clutch dog 23 intoengagement with the thrust bearing 22' to shift the sheave 18 intoengagement with clutch plate whereby the drive shaft 15 will rotate in adirection opposite to that of the motor shaft 9 since the V-belt 17 iscrossed. In normal disposition, the sheaves 13, 18, will be in alignmentwith pulleys 10, 11. Thus, when the same are shifted into frictionalengagement with clutch plate 20, the same will be out of alignment,whereby the sheave 13, 18, as the case may be, opposite to that beingmoved into engagement will runningly return to aligned relation with itsrelated pulley through the inherent tendency of the belt trained thereonto run between parallel centers, and, consequently, lose engagement withthe clutch plate 20 thereby. For normally urging the bell crank 29 intoneutral position there is provided within housing 2,

a link 36 which is engaged at one end to the arm 3i of bell crank 29,and projects at its other or forward end through a sleeve 37 suitablyfixed to the inner face of side wall 4'. Encircling the link 36 insleeve 37 is a spring 38 which bears at its ends against collars 39, 48,mounted on the iink 36 (see Figure 14).

Forwardly of housing 2 the frame 1 comprises a generally open-type boxstructure formed by a pair of sidc` members 41, 41', and an end orso-called front box 42 having a top plate 43, side plates 44, 44', thelatter being welded to the side members 41, 41', respectively, adjacenttheir forward ends, and an end plate 45 spaced from the forward ends ofthe side members 41, 41' (see Figure 6). Side members 41, 41', are eachformed of a pair of track sections 46, 46', rectangular in cross sectionhaving transverse webs 47, 47', respectively, weldedly secured togetherin back to back relation, so that the track section 46 will be insuperimposed relation to the track section 46' (see Figure 7). Each ofthe tracks 46, 46', is provided with a longitudinal opening 48, 48', intheir upper and lower walls respectively, which extend the lengththereof whereby the portions adjacent said openings 48, 48', willprovide spaced rails, generally designated 49. At their rearward endsthe side members 41, 41', project into the housing 2 through openingsformed in the opposite sides of the forward wall 6 in immediateadjacency, and secured, to the inner faces of the side walls 4, 4',respectively; said members 41, 41', terminating forwardly of the driveshaft 15 (see Figure 2).

Guidedly extending through the upper and lower tracks 46, 46', of eachside member 41, 41', are the upper and lower lengths of drive chains 50,50', respectively, the rearward ends of which are engaged about sprocketwheels 51. 51. respectively, mounted for rotation upon the drive shaft15 at opposite ends thereof inwardly of the side walls 4, 4'. Theforward ends of the drive chains 50, 50', are trained about sheaves 52,52', respectively, xed on opposite ends of an idler shaft 53, extendingtransversely between the side plates 44, 44', of the front box 42 andbeing journaled at its ends in slot-like openings 54 formed in each sideplate 44, 44'. Secured to the idler shaft 53 on opposite sides of eachsheave 52, 52', are collar bearings 55 for maintaining said sheaves 52,52', in alignment with sprocket wheels 51, 51', respectively. Said idlershaft 53 passes through the eyelets of eye bolts 56, 56', the shanks ofwhich pass through apertures provided in the end plate 45 and have nutsthreadedly engaged thereon to permit adjustment of the idler shaft 53 bymovement through the slots 54 to assure desired tension of the drivechains 50, 50'.

The operating lever 34 is mounted on one end of a rock shaft 57 whichextends through vertical slot-forming openings 62, 62', in the sideplates 44, 44', respectively, for spanning the distance between saidplates and being relatively movable in said openings 62, 62'. Fixed oneach projecting end of the rock shaft 57 are identical cam followers 58,58', having a notch or recess 59 in their lower peripheral portion fornormal engagement with cam disks 60, 60', mounted on the side plates 44,44' (see Figures 9 and l0). whereby the shaft 57 will be normallydisposed at the lower end of said openings 62, 62. Outwardly of camfollowers 58, 58', the rock shaft 57 engages the upper ends ofconnecting links 61, 61', which, at their lower ends, are engaged to theends of a rod 64 projecting through apertures 63, 63', similar in allrespects to openings 62, 62', provided in the side plates 44, 44', re-

spectively, and extending transversely between said plates proximatetheir lower ends. Thus, as will be more fully shown below, the rod 64and shaft 57 will move relatively upwardly in the slots 63, 63', and 62,62', respectively, upon operation of the cams and cam followers. Theconnecting links 61, 61', are each maintained against untoward lateralshifting upon the rod 64 by spacer members generally designated 65 fixedupon said rod 64 on opposite sides of said connection links 61, 61'.Rigidly secured to the rod 64 on either end thereof, immediatelyinwardly of the side sections 44, 44', are vertically presented,parallel latch arms 66, 66', respectively, each having pivotally engagedadjacent its lower end, on the inner side thereof, a latch member 67,67', respectively, for locking engagement with a latch bar 68 anchoredupon the forward end of the table B. Each latch arm 66, 66', and latchmember 67, 67', has provided on their forwardly presented marginsprojecting studs 69, 69', respectively, for securement thereto of theends of an extension spring 7i) for normally biasing the latch members67, 67', rearwardly. Protruding from each latch member 67, 67', is atransverse stop pin 71 for detaining abutment against the forwardlypresented margin of the associated latch arms 66, 66', to limit therearward pivotal movement of the latch members 67, 67'.

Fixed, as by welding, to the rod 64, at the midpoint thereof, is thelower end of an upstanding arm 72, preferably of at steel construction,having its upper end iixedly connected to the forward end of a slide rod73 which extends longitudinally between the side members 41, 41', inparallel relation thereto, and being turned down at its rearward end, asat 74, for projection through an opening 75 in the front wall 6 a shortdistance into housing 2. Encircling the turned down portion 74 of theslide rod 73, within the housing 2, is a relatively heavy compressionspring 76 which bears at its forward end against the inner face of thefront wall 6 and at its opposite end against a collar 77 maintained onthe slide rod 73 by a nut 78. Forwardly of front wall 6 there issurroundingly disposed upon the turned down portion 74 a relativelylight compression spring 79 bearing at its rearward end against theouter face of front wall 6 and at its forward end against a collar 80abuttingly presented against the shoulder 81 formed by the turning downof portion 74.

Said slide rod 73 is provided substantially throughout its length with aplurality of spaced, transverse bores 82 for selective alignment withopposed openings 83 formed in the lower sleeve-forming portions 84, 84',of a pair of cylindrical detent members 85, 85', respectively, mountedby said sleeves 84, 84', on the slide rod 73 for slidable movement intodesired spaced positionment thereon. Removable locking pins 86 areprovided for reception in an aligned bore 82 and openings 83 formaintaining the detent members 85, 85', in selected location upon theslide rod 73. At their confronting ends, the detent members 35, 85', areformed to provide flared mouths 87, 87', respectively, and at theiropposite ends each has an air hole 88, 88', respectively, drilledcentrally in its end wall. Presented for bearingwise abutment againstthe confronting ends of the sleeves 84, 84', are compression springs 89,89', respectively, having their opposite ends bearing against collars90, 90', respectively, adjustably engaged upon the slide rod 73.

Within the lower lengths of each sprocket chain 50, 50', there isengaged a truck member 91, 91', respectively provided at each of itsends with a pair of rollers designated r, for movement along the rails49 of each lower track 46'. Centrally each truck member 91, 91', isprovided with a vertically extending sleeve 92, 92', respectively, forreceiving the upper ends of support posts 93, 93', of a squeegeecarriage, denoted C. Engaged upon the posts 93, 93', in a free fittingmanner, for extension therebetween is a crown piece or bar 94 having itsends maintained in horizontal alignment by nuts 95 threaded on each post93, 93', above and below the crown piece 94. Downwardly from the crownpiece 94 there is suitably mounted upon cach post 93, 93', a collar 96,96', respectively, having bearing against its under face the upper e-idof a compression spring 97, 97', respectively, the lower ends of whichbear against the upper surface of a block 98, 98', respectively,fabricated preferably of aluminum, being slidably disposed on each post93, 93', and each being supported on their under surface by a washer 99and nut 100 threaded on the lower end of each post 93, 93'. Thus thesprings 97, 97', urge the blocks 98,

98', respectively downwardly. Each block 98, 98', is provided with apair of vertically spaced longitudinally extending taps 101, 102, forthreadedly receiving adjustment screws 103, which project through theforward face of the blocks 98, 98', for abutment against a squeegee bar104, preferably of wood, and extending from side to side of the carriageC with its ends terminating outwardly of the posts 93, 93', and beneaththe lower tracks 46. Mounted in the face of the squeegee bar 104 opposedto the blocks 98, 98', is a pair of yoke-forming brackets 105 engagedfor pivotal connection to said blocks 98, 98', as may best be seen inFigure 6. By threading of the adjustment screws 103, the squeegee bar104 may be presented at an angle to the vertical so that a rubber strip0r squeegee 106 received within a groove on the under margin of the bar104 will assume a like angle.

Weldedly secured to the upper face of the crown piece 94 centrallythereof is the lower end of a vertically presented arm 107 provided withan opening 108 for relative movement therethrough of the slide bar 73and being xedly engaged adjacent its upper end to the middle portion ofa piston-forming rod 109, axially normal to the arm 107. At each end ofthe piston rod 109 there is mounted a pair of buffer disks 110, 111,made preferably of leather, and having beveled margins, as at 112, inopposed direction, as is clearly shown in Figure 6. Said pairs of disks110, 111, are each aligned with a detent member 85, 85', respectively,for shock cushioning movement therein upon traverse of the squeegeecarriage C, as will be described hereinbelow.

As may best be seen in Figure l, there is welded to the bottom margin ofthe front wall 6 of housing 2 a pintle 113 extending at its ends beyondthe side walls 4, 4', for engagement within bearing blocks 114, 114',bolted to the upper face of the table B whereby the printing machine Ais fulcrumed for pivotal movement between the upward or unlatchedinoperative position shown in Figure l and the downwardly, latched,horizontal position shown in Figure 6. Engaged to the rearward end wall5, substantially centrally thereof and proximate its lower margin is oneend of a heavy extension spring 115 projecting forwardly and downwardly,having its forward, lower end engaged to a turnbuckle 116 which is, inturn, engaged to a brace 117 upon the table B. Thus, by adjustment ofthe turnbuckle 116 the tensioning of the spring 115 may be controlledfor proper counterbalancing of the machine A for purposes to bedescribed hereinbelow. Secured centrally to a bar 118 extendingtransversely between the side walls 4, 4', and suitably secured at itsends thereto is the upper end of a shock absorber member 119, the lowerand forward end of which is engaged to the table B. Thus, by operationof said shock absorber 119, untoward jarring of the machine A uponswinging thereof about its fulcrum will be prevented.

Provided for disposition upon the upper surface of the table B is ascreen 120 having a frame 121 which is adapted for pivotal engagement atits rearward margin to the table B as at 122, whereby the screen 120 maybe elevated at its forward end to permit the insertion of blank worksheets therebeneath. The screen 120 may be of suitable fabric or, ifdesired, may be replaced by a stencil. Provided on said screen 120 maybe a single design or a plurality of designs for more than one color,for transference to the blank work sheet; said design portions beingpervious to coloring matter, which is customarily a paintlike material.At its forward end the frame 121 is centrally provided with an eyelet123 for engagement to a latch member 124 which is secured to a chain 125depending from the under surface of top plate 43; said chain 125 andlatch 124 are of such combined length that when the machine A is inupwardly tilted position, as shown in Figure l, the screen frame 121will be out of axial horizontal parallelism with the machine A and will,thus, be suspended slightly below the forward portion of frame 1.

Provided at the rearward end of the screen 120 and supported by theadjacent portions of the frame 121 is an upstanding paint guard orreceptacle 126 to prevent overflow of the paint when the same isdirected rearwardly during the printing stroke of the squeegee carriageC or upon upward swinging of the screen 120 when the machine A is rockedinto the position shown in Figure l.

To assure proper presentation of paint to the squeegee 106 for evendistribution across the screen 120 there is provided a scoop assembly127 comprising spaced angle members 128 secured to the upper surfaces ofthe squeegee bar 104 for disposing one of its flanges 129 in spacedparallel relation to the normally rearward face of the bar 104. Fixed tothe lower portions of the ilanges 129 is a transversely extending tray130 spaced from the squeegee 106 and inclined toward same so that paintthereon may ow through gravity for presentation immediately in advanceof the squeegee 106, as it travels rearwardly. Mounted on the uppersurface of the squeegee bar 104 are spaced bearing members designated131 for journaling therein of a shaft 132. Engaged to one end of saidshaft 132 is the upper end of a link 133 having secured to its lower endan outwardly projecting arm 134 upon which is fixed a cam follower 134'disposed for engagement with a cam block 135 mounted on the screen frame121 adjacent its forward end.

v Welded to the shaft 132 are the upper ends of a plurality of spacedwires 136 which are supportingly connected to a wiper blade 137 disposedwithin the tray 130 for sweeping movement thereacross, as will bediscussed here- Jnbelow. Engaged about the shaftY 132 are a pair of,-'helical twist springs 138, 138', the ends of which abut against thebearings 131 and adjacent wires 136 (see :Figure 13) to bias the shaft132 so that the wiper blade 137 will be normally disposed at therearward side of tray 130, remote from the discharging margin thereof.

I n order to describe the operation of the machine A, which is cyclicalin nature, it will be presumed that the machine A is in downward latchedposition as shown in Figure 6, with the squeegee carrier C disposed atthe forward end of the machine, the buffer disks 110, 111, being engagedwithin the cylindrical detent member 85'. With the motor actuated, theoperator will grasp the handle grip 35 of lever 34 and push the lowerend thereof downwardly and rearwardly to cause the sheave 13 to engagethe friction clutch 20 whereby rotation of the drive shaft 15 Vwilleffect movement of the drive chains 50, 50'. The lower lengths of saidchains 50, 50', will travel rearwardly causing the truck members 91,91', to be moved along the rails 49 thereby carrying the squeegeecarrier C rearwardly with sweeping by the squeegee 106 of the printingpaint over the design portion of the screen 120 for imprinting of thedesigns on the blank work sheet.

By such downward rocking of the handle end of the lever 34, the camfollowers 58, 58', will be rotated so that the cams 60, 60',respectively, will move relatively out of the notches or recesses 59 andonto the adjacent peripheral portion of said follows 58, 58', wherebythe forward end of frame 1 will be rocked downwardly with the rock shaft57 and rod 64 abutting against the upper ends of the slotlike openings62, 62', 63, 63' (see Figure l0). The depth of the notches or recesses59 thus determine the extent of such rocking of the frame 1. This actionserves to bring the squeegee 106 into tight, pressure-producing contactwith the screen 120, as shown in Figure ll.

The length of the printing stroke or rearward traverse of the squeegeecarrier C will be determined by the movement of the piston rod 109within the cylindrical detent member 85 whereby the buffer disks 110,111, will snugly engage the walls thereof in compression of the airtherein, with pressure relief through the air hole 88, all in the mannerof a dashpot. The force of the impact of the buffer disks 110, 111, andthe detent member 85 will be transmitted to the slide rod 73 causingsame to move linearly rearwardly in compression of the springs 76, 79.This movement of the slide rod 73 will cause the arm 72 to be pulledrearwardly at its upper end whereby the rod 64 will be rocked withconsequent tilting of the latch arms 66, 66', to effect pivotal movementof the latch members 67, 67', into unlocked position. The operator willthen release the lever 34 to permit same to return to neutral position.With the spring properly adjusted, the machine A will have its center ofgravity shifted rearwardly by the arrival of the squeegee carrier C atthe end of its printing stroke so that upon unlocking of the latchmembers 67, 67', in the manner just described, the machine A will pivotabout its fulcrum with the rearward portion swinging downwardly and theforward frame portion swinging upwardly into the position shown inFigure l. The screen will be swung upwardly about its pivot 122 by suchupward rocking of the machine A, however, because of the combined lengthof the chain and latch 124, the screen 120 will hang sufficientlybeneath the squeegee ,106 to prevent unauthorized contact therebetween.With the machine A in upper unlocked or inoperative position, the fullyprinted work sheet may be removed and a blank readily placed intoposition for the next printing operation.

The operator will next rock the operating lever 33 into the positionshown in Figure 9 so that the sheave 18 will be brought into engagementwith the friction clutch to cause the drive chains S0, 50', to move in areverse direction whereupon the squeegee carrier C will move forwardlyfor return to initial or starting position, with such forward travelbeing determined by engagement of the appropriate buffer disks 110, 111,within the cylindrical detent member 85. The machine A is socounterbalanced that upon arrival of the squeegee carrier C at itsstarting point the center of the gravity will have shifted so that theforward end of the machine A will descend causing the latch member 67,67', to engage the latch bar ,68 whereby the machine A will be presentedin substanltially horizontal position with the screen 120 resting uponthe table B in covering relation to the newly inserted blank work sheet.It will thus be seen that as the squeegee carrier C moves forwardly themachine A will be slowly rocking downwardly at its forward end until itis in fully latched position upon completion of the return stroke of thesqueegee carrier C.

As stated above, the detent members 85, 8S', may be mutually disposedupon the slide rod 73 to present any selected distance therebetweenwhereby the extent of the printing stroke of the squeegee carrier C willbe determined. Consequently, if the particular area of the screen 120containing the design to be transferred was relatively small, the detentmembers 85, 85', would be commensurately positioned so that the squeegeecarrier C would traverse a distance corresponding to the extent of thedesign during the printing stroke. It will thus be seen that byutilization of the detent members 85, 85', unnecessary travel of thesqueegee carrier C is eliminated and the machine A is provided therebywith marked versatility for accommodating designs or printing portionsof varying lengths and widths. Furthermore, it is to be noted that thesqueegee carrier C can be readily adapted for operation with screens ofvarious dimensions. For instance, if an elongated relatively narrowscreen were to be utilized, a squeegee bar having a corresponding narrowrubber strip or squeegee could be inserted in the carrier C for printingtraverse along the narrow screen. In view of the above, it is apparentthat the machine A is highly adaptable for use with an extensive varietyof blank work material, as well as screens or stencils of differentdimensions.

The scoop assembly 127 will operate as follows, upon actuation of themachine A: Upon arrival of the squeegee carrier C at the end of theprinting stroke, paint held on the screen within the paint guard 126will be scooped up by the tray 130 and held thereon, as the machinetilts upwardly into unlatched position, by the upward movement of thesaid tray 130. Thus, the paint will remain on the tray 130 as thecarrier C is returned to starting position with the cam 134' clearingthe cam block 135 on such return movement due to the slight upwarddisposition of the frame 1 with regard to the table B prior to actuationof the lever 34. When the operator rocks the lower end of lever 34downwardly for commencement of the printing stroke, the cam follower 134will engage the upper, straight surface of cam 135 whereupon the shaft132 will be rocked against the pressure of the springs 138, 138', withconsequent sweeping movement of the wiper blade 137 across the face ofthe tray 130, from the normally rearward end thereof to the dischargeend thereof. to cause the paint held thereon to be wiped off fordischarge immediately in advance of the squeegee 106. The Cam follower134 will thus travel down the inclined face of cam block 135 to permitthe shaft 132 to return to normal position under the load upon thesprings 138, 138, with restoration of the wiper blade to the normallyrearward portion of the tray 130. Thus, by the unique operation of thescoop assembly 127, paint will be positively and assuredly presented tothe squeegee 106 for effective printing in an even manner.

Thus, the machine A presents a compact unit which may be easilyinstalled upon any suitable work support that the user may have. It isto be particularly noted that the drive means are contained within thehousing 2 which is integral with the frame 1 so that a user would haveno involved installation problems, such as is present in currently usedmachines of this type wherein motors must be separately mounted, anddrive chains and the likt? properly connected before operation can beinstituted. The counterbalancing means provided in machine A assureproper printing action and permit insertion of blank work sheets at theappropriate juncture. Thus, an operator of such a machine need not beparticularly skilled since all that is required is the mere placing ofthe blank work sheet and the appropriate movement of the lever, asdiscussed hereinabove, since the machine A will automatically positionitself properly at all times.

It should be understood that changes and modifications in the form,construction, arrangement and combination of the several parts of thescreen printing machine may be made and substituted for those hereinshown and described without departing from the nature and principle ofthe present invention.

What I claim and desire to secure by Letters Patent is:

l. A screen printing machine comprising a frame, a squeegee carriermounted in said frame for traversing movement to present a squeegeesupported thereby for printing engagement upon a screen, drive means foractuating said squeegee carrier, a double-headed piston-forming memberprovided on said squeegee carrier and axially parallel to the line ofmovement of the squeegce carrier, a rod mounted in said frame inparallel relation to the piston-forming member for relative movementtherealong of the squeegee carrier, and a pair of opposed cylindricaldetent members selectively positionable upon said rod for engagementwith opposite heads of said piston-forming member for determiningthereby the extent of traversing movement of the squeegee carrier.

2. A screen printing machine comprising a frame, a squeegee carriermounted in said frame for traversing movement to present a squeegeesupported thereby for printing engagement upon a screen. drive means foractuating said squeegee carrier, a double-headed piston-forming memberprovided on said squeegee carrier and parallel to the line of movementof the squeegee carrier, a rod mounted in said frame in parallelrelation to the piston-forming member for relative movement therealongof the squeegee carrier, and a pair of cylindrical detent members havingconfronting flared month portions for reception of opposite heads ofsaid piston-forming member for arresting movement of the squeegeecarrier, said detent members being selectively positionable upon saidrod whereby the extent of travel of the squeegee carrier can beoptionally determined.

3. A screen printing machine comprising a frame. a squeegee carriermounted in said frame for traversing movement to present a squeegeesupported thereby for printing engagement upon a screen. drive means foractuating said squeegee carrier, a double-headed piston-forming memberprovided on said squeegee carrier. a rod provided in said frame forrelative movement therealong of the soneegee carrier, a pair of oonnceddetent members selectivelv positionable upon said rod for enga gementwith opposite heads of said piston-forming member for de.- tei-miningthe extent of travel of said soneegee carrier. said rod being` mountedfor linear movement non engagement of said detent members bv thepiston-forming member. latch means for locking said frame tn the worksnnnnrt surface. and rneans connecting seid rod and said lntrh means foreffecting disengagement of same nnnn linear movement of said rod whenone of said detent members is engaged.

4. A screen printing machine comprising a frame. a squeegee carriermounted in said frame for traversing movement to present a soueegeesupported therebv for printing engagement upon a screen. drive means foractuating said squeegee carrier, a paint scoop device mounted on saidsqueegee carrier for movement therewith and comprising a tray disposedadjacent the squeegee for receiving paint, a shaft journaled in bearingsupon the squeegee carrier, a wiper blade supported by said shaft fordisposition on said tray, resilient means for urging said shaft intoposition for disposition of the wiper blade at the end of said trayremote from the squeegee, and cam means for rocking said shaft at apredetermined point of travel of said squeegee carrier in order to causesaid wiper blade to be moved across said tray for discharge of paintheld thereon to deliver same to the screen as the squeegee commences itsprinting stroke.

5. A screen printing machine comprising a frame, a squeegee carriermounted in said frame for traversing movement to present a squeegeesupported thereby for printing engagement upon a screen, drive means foractuating said squeegee carrier, a slide rod provided in said frame,cooperating motion interdicting members for determining the extent oftravel of said squeegee carrier, said slide rod being adapted formovement upon engagement of said cooperating motion interdictingmembers, latch means for locking said frame to a work support surface,and means connecting said slide rod and latch means for tripping saidlatch means upon movement of said slide rod in one direction.

6. A screen printing machine comprising a frame, a squeegee carriermounted in said frame for traversing movement to present a squeegeesupported thereby for printing engagement upon a screen, drive means foractuating said squeegee carrier, a slide rod provided in said frame,cooperating motion interdicting members for determining the extent oftravel of said squeegee carrier, said slide rod being adapted formovement upon engagement of said cooperating motion interdictingmembers, at least one latch member for locking said frame to the worksupport surface during printing operation, a link secured to said sliderod, and means connecting said link and said latch member for trippingsaid latch member upon movement of said slide rod in one direction.

7. A screen printing machine for disposition upon a work support surfacecomprising a frame, a squeegee supported thereby for printing engagementupon a screen, drive means for actuating said squeegee carrier, anabutment member provided on said squeegee carrier, a rod provided insaid frame for relative movement therealong of the squeegee carrier, apair of opposed detent members provided on said rod for engagement withsaid abutment member for determining the extent of travel of saidsqueegee carrier, said rod being mounted for linear movement uponengagement of said detent members by the abutment member, at least onelatch member for locking said frame to the work support surface duringprinting operation, a link secured to said rod, and means connectingsaid link and said latch member for tripping of the latter upon linearmovement of said rod when one of said detent members is engaged.

8. A screen printing machine as described in claim 3 wherein the latchdisengaging means include a link secured to said rod, a cross rodextending transversely of the frame, said link being secured to saidcross rod, at least one latch arm secured to said cross rod, a latchmember pivotally engaged to said latch arm, and a resilient memberconnected at its ends to said latch arm and latch member.

9. A screen printing machine for demountable disposition upon a worksupport s urface comprising a frame, a squeegee carrier mounted in saidframe for traversing movement to present a squeegee supported therebyfor printing engagement upon a screen, drive means for actuating saidsqueegee carrier, a slide rod provided in said frame, means for mountingsaid frame upon the work support surface for rockable movement in avertical plane between horizontal or operative position and raised orinoperative position, cooperating motion interdicting members fordetermining the extent of travel of said squeegee carrier, said sliderod being adapted for movement upon engagement of said cooperatingmotion interdicting members, latch means for locking said frame to thework support surface when the said frame is in horizontal or operativeposition, means connecting said slide rod and latch means for trippingsaid latch means upon movement of said slide rod in one direction, andcounterbalancing means associated with said frame for causing upwardpivotal movement thereof into raised position upon tripping of saidlatch means.

10. A screen printing machine for demountable disposition upon a worksupport surface comprising a frame, a squeegee supported thereby forprinting engagement upon a screen, drive means for actuating saidsqueegee carrier, an abutment member provided on said squeegee carrier,a rod provided in said frame for relative movement therealong of thesqueegee carrier, means for mounting said frame upon the work supportsurface for rockable movement in a vertical plane between horizontal oroperative position and raised or inoperative position, a pair of opposeddetent members provided on said rod for engagement with said abutmentmember for determining the extent of travel of said squeegee carrier,said rod being mounted for linear movement upon engagement of saiddetent members by the abutment member, at least one latch member forlocking said frame to the work support surface during printingoperation, a link secured to said rod, and means connecting said linkand said latch member for tripping of the latter upon linear movement ofsaid rod when one of said detent members is engaged, andcounterbalancing means associated with said frame for causing upwardpivotal movement thereof into raised position upon tripping of saidlatch means.

References Cited in the le of this patent UNITED STATES PATENTS1,687,080 Beck Oct. 9, 1928 1,776,459 Tull et al. Sept. 23, 19301,922,710 Owens Aug. 15, 1933 2,207,818 Perry et al. July 16, 19402,315,730 Orthwine Apr. 6, 1943 2,571,685 DAutremont Oct. 16, 19512,610,579 Wing Sept. 16, 1952

